Hypertension, Or High Blood Pressure, Is One of the Most Common Forms of Cardiovascular

UNIVERSITY OF IDAHO

Hypertension PEP 493 Group Project (Spring 2012)

Becca Berger, Nicole Eidemiller, Hollie Garrison, Cameron Lorbiecki, Casey Schooley Hypertension, or high blood pressure, is one of the most common forms of cardiovascular disease (1). It refers to the force of blood pushing against artery walls as blood travels throughout the body (1). Blood fills arteries to a specific capacity, and too much pressure on the artery walls can lead to life-threatening conditions like heart disease and stroke. It is commonly called the “silent killer” because it hardly shows symptoms but results in serious health consequences (1).

Blood pressure is measured by ratio of two numbers, systolic over diastolic pressure. Systolic pressure is the pressure in the arteries when the heart beats and fills the vessel with blood. Diastolic pressure is the pressure when the heart is at rest. Normal blood pressure is systolic lower than 120 mm/Hg and diastolic lower than 80 mm/Hg (6,1,2). Prehypertension is classified as systolic between 120-139 mm/Hg and diastolic between 80-90 mm/Hg (6,2). Stage 1 hypertension has a systolic between 140-159 mm/Hg and a diastolic reading between 90-99 mm/Hg (6,2). Finally, stage 2 hypertension has a systolic pressure equal to or more than 160 mm/Hg, and diastolic is equal to or more than 100 mm/Hg (6,2).

Hypertension has been shown to be more prominent in people that have a family history of high blood pressure or diabetes, smoke, drink excessively, eat foods in high saturated fats or salts, are not physically active, greater than age 55, are African American, and are overweight (1,2). Some symptoms of hypertension include severe headache, fatigue, chest pain, difficulty breathing, irregular heartbeat, and a sensation of pounding in the chest, neck, or ears (1,2).

There are two types of hypertension, essential and secondary. Essential had no identifiable cause and tends to develop gradually over the years 11). Lifestyle behaviors such as poor diet and lack of physical activity are thought to have correlation with this type of hypertension, and it accounts for approximately 90 percent of hypertension cases (11). Secondary hypertension is caused by and underlying condition such as kidney problems, adrenal gland tumors, congenital defects in blood vessels, certain medications, and illegal drug use like cocaine and amphetamines (811). Uncontrolled hypertension can lead to heart failure, stroke, heart attack, weakened or narrowed blood vessels to the kidneys which can lead to renal failure, narrowed or torn blood vessels to the eyes which can cause vision loss, metabolic syndrome, and aneurysms (1,3,11). There are several reasons as to how hypertension could be caused. The renin- angiotensin-aldosterone system produces aldosterone which stimulates epithelial cells of the kidneys to increase the –reabsorption of salt and water (3). The result from this reabsorption of water and salt is increased blood volume and raised blood pressure (3). The autonomic nervous system plays an important role in cardiovascular homeostasis by regulating pressure, volume, and chemoreceptors. An overactive sympathetic nervous system increases blood pressure from a variety of mechanisms (3). Hypertensive patients do not show norepinephrine levels lowering blood pressure through regulating noradrenergic receptors, this results in decreased peripheral vascular resistance by adrenergic hyperactivity; this is thought to be a genetic response (4). Exposure to stress can increase sympathetic activation, and with repeated stress-induced vasoconstriction, this effect can cause vascular hypertrophy which can result in increased peripheral resistance (4). Known vasoconstrictors are angiotensin II, norepinephrine, thromboxane, and endothelin (4). Arteriosclerosis is the hardening or narrowing of the arteries from buildup of fat, cholesterol and other materials that form plaques, which can result in increased blood pressure (10). Consequently high blood pressure can cause arteriosclerosis as well by forcefully pushing the blood through the vessels causing the delicate lining known as the endothelium to stretch and injure (10). Injured endothelium attracts LDL cholesterol which causes the forming of plaque (10). The figure to the right demonstrates visually how arteriosclerosis has a constricting effect on arteries which increases blood pressure.

Effective prevention techniques are weight loss, dietary sodium reduction, increased physical activity, moderating alcohol consumption, and use of potassium supplements (7), (1). According to the Clinical Guidelines for the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults, individuals that lost 7.7 lbs. of body weight reduced their systolic and diastolic blood pressures by 5.8 and 3.2 mm/Hg (7). From the U.S. Department of Health and Human Services Guidelines for Primary Prevent of Hypertension: High Blood Pressure Education Program, a reduction of 77mmol/d of sodium decreased systolic blood pressure by 1.9 mmHg and diastolic blood pressure by 1.1 mmHg (7). The Department of Health and Human Services also stated that aerobic exercise decreased 4.04 mmHg in systolic blood pressure, reduced alcohol consumption decreased systolic blood pressure by 3.56 mmHg and diastolic blood pressure by 1.80 mmHg, and potassium supplements lowered systolic blood pressure by 1.80 mmHg and diastolic blood pressure by 1.00 mmHg (7).

a. What is the evidence that exercise prevents this disease?

According to the American College of Sports Medicine (ACSM), Position Stand on Exercise and Hypertension, hypertension is a preventable, treatable, and controllable condition. Lifestyle modifications are one way for individuals to lower their blood pressure (BP). These lifestyle modifications which involve aerobic exercise, decreases blood flow resistance for individuals with normal BP, as well as for individuals with hypertension. The most effective form of exercise that reduces BP readings is primarily aerobic activities (1). Prevention of hypertension is one of the main outcomes of aerobic training. According to a study done on male university alumni, continued vigorous exercise in the years after college indicates a lower risk of hypertension in their future; and in a study done to assess the Japanese men’s walk-to-work and leisure time physical activity and how it relates to hypertension, it showed a significant reduction against the risk of hypertension (1). In studies with women or black subject, there is not enough data to suggest that exercise is an effective way to prevent hypertension across ethnicity and sex (1). As stated before, aerobic training has been seen to have the most significant affect in the prevention of hypertension. Moderate levels of aerobic exercise at least 30 minutes a day, or most days of the week, is seen to be effective in preventing hypertension with exercise. Evidence shows that aerobic exercises also decreases resting BP. Several studies have demonstrated that a variety of different aerobic exercises, performed at 30-90% VO2max, demonstrates a significant decrease in resting BP. The effects of BP during exercise were difficult to determine because of differences in exercises performed, BP measurement methods, demographics, frequency and duration of exercise session (1). b. What is the evidence that exercise plays a role in managing and/or treating the disease? How effective?

Exercise has also been shown to have a significant effect on managing hypertension as well. In fact, the most impressive BP reductions are seen in individuals who are hypertensive and are engaging in exercise. In one study, result between participants who were hypertensive and normotensive engaging in the same exercise program showed highest reduction in resting BP among the hypertensive group (1). In another study “Aerobic training also reduces ambulatory BP and BP measured at a fixed submaximal work load.” (1) These BP responses typically differ among studies because of differences in FITT principal application. There is also an acute BP response after exercise. It has been discovered that aerobic exercise showed a decrease in a normally elevated BP into normotensive ranges for up to 22 hours after exercise. This is called post-exercise hypotension (1). This effect has been seen in people with and without hypertension, but is most significant among hypertensive individuals. BP reductions seen are diastolic BP and systolic BP of 15 and 4 mm hg from a preexercise value of 147/94. Therefore, aerobic training can be use a way to manage hypertension. In regards to the effects of resistance training, and its effect on hypertensive individuals; ACSM has concluded that “resistance training performed according to ACSM guidelines reduces BP in normotensive and hypertensive adults.” (1). These finding are based off the results of a study that examined the effects of chronic eccentric and concentric resistance training on resting BP in adults. Basically, resistance training showed a reduction in about 3 mm Hg in diastolic BP and systolic BP (1). Chronic isometric exercise resistance training shows reductions in BP. However, few studies have been conducted on isometric exercise and its reduction of resting BP in hypertensive individuals (1). Similarly, there are limited studies that demonstrate the acute effects of isometric on hypertensive individuals. Therefore, ASCM has no recommendations for using, or suggesting, isometrics for management of hypertension. Among men a women, resistance training has been shown to reduce BP similarly, but there is a lack of evidence to support any acute response differences across men and women (1). III. Exercise Prescription for Hypertension a. What exercise prescription guidelines are recommended in this population? Exercise prescription for patients with Hypertension is a fairly complicated process because there are many different stages of hypertension, and many other factors that alter the physical activity levels that can be prescribed to a hypertensive patient. Due to the complexity of prescribing exercise to this population, it is very important that patients obtain a physician’s clearance before participating in any exercise programs. This ensures the safety of each individual patient by assessing the severity of their hypertension so that the proper exercise regimen is prescribed. Once a patient has received a physician’s clearance and is capable of participating in a prescribed exercise, a general routine can most often be assumed. For the majority of the hypertensive population, moderate intensity has been shown to be the most effective in lowering the patient’s blood pressure. Therefore, moderate intensity is usually prescribed to hypertensive patients. Sources such as ACE and ACSM recommend at least 30 minutes of moderate intensity activity at least 5 days a week (15). Participating in regular physical activity reduces the relative risk of Hypertension 19-30%. Since regular physical activity has shown a reduced relative risk, if a patient is capable of participating in exercise every day of the week it is strongly advised in this population. However, if a patient has a low fitness level when beginning physical activity, they should begin all exercise routines at a shorter duration. Once the patients have progressed in their exercise routine, time should be added to their sessions to continue progress (15). Unfortunately in the hypertensive population, the general exercise prescription provided above is not compatible with all individual circumstances. Luckily, there are many alterations that can be made to fit the needs for each category of Hypertension. This allows physicians to personalize the regimens that they are prescribing in order to better serve the population, as well as ensure that the most effective routine is provided to each patient. The American College of Sports Medicine places hypertensive patients into one of three categories based on the severity of their Hypertension. This placement allows for a more effective prescription of exercise based on the needs of the patient. The categories place patients based on the Grade of Hypertension (based on the severity of the patient’s blood pressure) with Grade 1 being the most mild and Grade 3 being the most severe, suspected Cardiovascular Disease, and even age of the patient. The combination of these factors places each patient into one of the three categories, which then allows physician’s to select the appropriate form of exercise (10). For patients who fall into “Column A” which is the most mild Hypertension and no suspected Cardiovascular Disease (CVD). If a patient falls into this category, aerobic activities such as walking, jogging and swimming are recommended as well as some resistance training in order to maintain their lean muscle mass. Patients in Column A are advised to participate in their exercise routine 6-7 days a week for about 30-60 minutes a day at a comfortable pace (moderate intensity). Once a patient has become comfortable with the exercise routine at moderate intensity, they can begin exercising at a higher percentage of their maximum heart rate (recommended increase up to 85%) (10). Patients who are placed into “Column B” have hypertensive values that are considered mild, some patients in this column have suspected Cardiovascular Disease, and some patients who are placed into this column are pre-hypertensive but are at an age that places them at a higher risk. If a patient falls into this category, walking and cycling are recommended in combination with resistance training to maintain muscle mass. Exercise monitoring is recommended for patients who have been sedentary, and monitoring should take place for patients who do not feel comfortable with the exercises they are given. Patients in this category should participate in exercise for 20-30 minutes a day for 5-7 days a week. It is important that the intensity is slightly lowered for patients who are placed into this category, while most hypertensive patients exercise at moderate-vigorous intensities, these patients should not. Light-moderate intensity is best for these patients until they have been conditioned and then the intensity can be increased (10). The last column in this model of classifying hypertensive patients, those who are hypertensive and have suspected Cardiovascular disease are placed into “Column C.” These patients should participate in low-impact activities such as walking, and as with the other categories, resistance training should be incorporated to maintain muscle mass. Patients in this category should participate in exercise 5-7 days a week and should start exercise at a lower intensity for about 20-30 minutes a day. Exercise monitoring is highly recommended in patients who fall into this category due to the severity of their hypertension. As patients progress in their exercise performance, they can increase their intensity up to light-moderate level, and increase their exercise sessions to about 30-60 minutes a day (10). Circuit training has also been shown to be an effective form of exercise for those with Hypertension. Circuit training is more effective than the use of free weights in exercising, but is only beneficial is precautions are followed. It is very important that hypertensive patients breathe correctly during their training, because improper breathing (holding your breath during weight training) can lead to unsafe fluctuations in blood pressure, which can cause a patient to faint. In some hypertensive patients, this fluctuation in blood pressure can be fatal. If circuit training is prescribed to a patient with Hypertension it is strongly advised that the weight training portion is monitored for the safety of the patient. b. What intensity, duration, frequency and mode are recommended (FITT principle)? As mentioned earlier, there is not one specific exercise recommendation for those who are hypertensive, so the values that are provided are generalized to the population. For the most effective exercise prescription patients should have the severity of their Hypertension examined by a physician. According to the FITT principle, patients with Hypertension should exercise at a moderate intensity which is defined as working at 40-60% of the patient’s maximal heart rate (3).Hypertensive patients should participate in an exercise regimen at least 5 days a week, but 7 days a week if possible for the patient (10,11). Patients should try to exercise at least 30 minutes a day, with a goal of reaching the capability to complete an exercise session of 60 minutes (10, 11). It is important to note that the 30 minutes of exercise does not need to be achieved in one exercise session, so it is possible to complete 10 minute bouts of exercise that accumulate to 30 minutes a day. This makes exercising easier for those who were sedentary. Continuous, rhythmic aerobic exercise has been shown to be the most beneficial in this population but it is possible to participate in endurance exercises or resistance training and see similar results (10, 11). It is important to note that resistance training should not be the primary mode of exercise in this population. The chart provided below summarizes the FITT principle recently described.

F (Frequency) Preferably 7 days a week I (Intensity) Moderate T (Time) 30 minutes a day T (Type) Continuous, Rhythmic and Aerobic ii. How should intensity of exercise be prescribed/monitored in this population?

For an individual with hypertension, they should be working out at moderate intensity. When starting an exercise program, an individual should aim at the lowest part of their target zone (50 percent) during the first few weeks. The individual should gradually build up to the high part of their target zone (85 percent). After six months or more of regular exercise, the individual may be able to exercise comfortable at up to 85 percent of their maximum heart rate. Hypertensive individuals should also be sure to prolong their cool-down to ensure their heart rate and blood pressure decrease properly.

There are many medications known as antihypertensive that are available by prescription to help lower high blood pressure such as Diuretics, Beta-blockers, ACE inhibitors, Angiotensin II receptor blockers, Calcium channel blockers, Alpha blockers, Alpha -2 receptors agonist, Peripheral adrenergic inhibitors, and Blood vessel dilators, or vasodilators. It is generally safe to exercise while on blood pressure medication, and doctors often prescribe both medication and exercise to treat hypertension. If fact, if someone is already taking medication for high blood pressure, adding regular exercise may help them lower the dose. A few high blood pressure medications lower the maximum heart rate and thus the target zone rate.

All antihypertensive medicine has some common of side effects such as fatigue, dizziness, or drowsiness, but there are some an individual must be aware of when choosing to participate in an exercise program. Both beta-blockers and calcium channel blockers decrease blood pressure as well as heart rate which could effect on an individual target heart rate by thinking that their heart rate is lower than what it really is. Another antihypertensive medication affects an individual’s heart rate by increasing and that is alpha blockers. With an increased heart rate it could affect the target heart rate while exercising as well. Individuals should have their blood pressure checked on a regular basis to make sure their values are being kept within a desirable range.

If it is difficult for an individual to monitor their heart rate especially if they are taking medications that might affect their heart rate there are various tests to determine if the individual is reaching a moderate level of intensity. If the individual can easily carry on a full conversation and perform the activity at the same time, they probably aren’t working hard enough. If the individual can exchange brief sentences easily while performing the activity, but not a comfortable or lengthy conversation, their intensity level is likely on target. If the individual gets out of breath quickly, or if short sentences feel like a strain, they are probably working too hard, especially if they have to stop and catch their breath. iii. What type of training is appropriate for this population - endurance training, strength training, yoga, swimming, etc.? Exercise for individuals with hypertension should consist of aerobic activities at least three days per week for 30-60 minutes, but could be done daily at moderate intensity. Some activities to choose from are brisk walking, hiking or stair climbing; jogging, running, bicycling, rowing, or swimming; fitness classes at the individuals appropriate level; team sports, dance class or fitness games.

Resistance training is important, but should only be done two times per week, with an emphasis on lower weight but higher repetitions (8-12 reps). Lifting heavy weight will increase the individual’s blood pressure which could cause problem with them already experience high blood pressure. There must be slow and in control movement to avoid a fast spike in blood pressure. Static stretching should be performed during each exercise session to help minimize the risk of musculoskeletal injury.

iv. What are the contraindications or complications with exercise for this population? What factors/things should be monitored before, during, after exercise?

a. Contraindications or complications of exercise with a hypertensive population (1)

With exercise and this population, there are a certain criteria to prevent further damage to the already injured person. These are absolute contraindications which stops the test immediately and relative contraindications which are pre-warning signals to be aware of. The absolute contraindications are as follows:

a.i.1.a.i. Aortic aneurysm a.i.1.a.vi. Myocarditis

a.i.1.a.ii. Aortic Stenosis a.i.1.a.vii. Pulmonary or systemic embolism a.i.1.a.iii. Crescendo Angina a.i.1.a.viii. Thrombophlebitis a.i.1.a.iv. Decompensated congestive heart failure a.i.1.a.ix. Ventricular Tachycardia or other dysthymias. a.i.1.a.v. Myocardial infarction

The relative contraindications are as follows: i. Aortic stenosis vi. Ventricular aneurysm

ii. Subaortic stenosis vii. Hypertension-untreated or uncontrolled sever iii. Marker cardiac systemic or pulmonary enlargement viii. Hypertrophic iv. Supraventricular cardiomyopathy dysthymias ix. Compensated congestive v. Ventricular ectopic heart failure activity

x. With exercise and a hypertensive population, more than likely a patient will be on a medication that will have an effect on their body during exercise. As an example, a beta-blocker is used to stop a heart from over-beating and maintains a constant max heart rate. During exercise this is problematic if a patient is at a higher intensity but the heart is not pumping out enough blood to provide the services muscles are rendering for. Monitoring in this population can be done so by determining their maximal heart rate with how exerted the patients feels at a certain intensity (9, 16).

xi. Sometimes women develop high blood pressure during pregnancy. If this is the case, blood that is directed towards the fetus will not go there but elsewhere during exercise. This is problematic during the development stages of the baby and should be noted before exercise begins. xii. Pre-existing organ damage or disease with exercise can cause further damage to the organs. Organs such as the kidneys with end-stage renal disease limits the daily activities a person can do as is and with exercise, it puts on a higher strain to that organ. xiii. The intensity of the exercise can cause a heart attack, or even after the exercise. With people already having hypertension issues and with exercise increasing their heart rate back up to a dangerous area, it is a complication if the patient does not report signs or symptoms of an issue or if the tester fails to watch the patient throughout the exam and they get overworked.

xiv. No exercise with a patient of a resting systolic pressure of >200mm Hg or diastolic pressure of >110 mm.

xv. If a patient has uncontrolled hypertension, exercise is not recommended until after initiating a drug treatment. b. What factors/things should be monitored before, during, after exercise?

xvi. Before exercise, record medications that a hypertensive patient may be taking. (i.e., beta-blocker, nitrates, calcium channel blockers, digitalis, diuretics, vasodilators, antiarrhythmic agents, nicotine, antihistamines, and diet pills). Thermoregulation may be a problem do to diuretics and beta blockers. Record resting blood pressure and heart rate prior to testing and note any signs or symptoms of discomfort from patient as chest comfort is qualified enough to stop exercise testing.

xvii. During exercise blood pressure should be systolic ≤220 mm Hg and diastolic ≤105 mm Hg. During exercise watch the patient for any signs of weakness, skin color change, dizziness, or if they are uncoordinated which are known to show. (Note it is called the silent killer for a reason). During exercise monitor the patients’ blood pressure. If on a beta-blocker, their heart rate will limit itself so do not exceed the known limit. Any unusual rises or dips in the systolic or diastolic once exercising are indications to stop.

xviii. After exercise the patient still needs to be monitored as the systolic and diastolic blood pressures should be decreasing by around 15% per minute after exercise. Note with hypertensive patients whom exercise it is common to see a rise in blood pressure of up to 22 hours post-exercise. Some medications such as beta blockers and calcium channel blockers can cause the sudden drops in blood pressure after exercise.

xix. Responsibilities: xx. Becca- Background

xxi. Casey- Role of exercise

xxii. Nicole- Prescription

xxiii. Hollie- Intensity and type of training

xxiv. Cameron- Contraindications, monitoring factors and outline design

xxv. References:

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9. Linda S. Pescatello, Ph.D., FACSM, (Co-Chair), Barry A. Franklin, Ph.D., FACSM, (Co-Chair), Robert Fagard, M.D., Ph.D., FACSM, William B. Farquhar, Ph.D., George A. Kelley, D.A., FACSM, and Chester A. Ray, Ph.D., FACSM, Exercise and Hypertension Medicine & Science in Sports & Exercise, 2004; 533-553National Institutes of Health and National Heart, Lung, and Blood Institute. National high blood pressure education program guidelines for primary prevention of hypertension. Available at: http://www.nhlbi.nih.gov/health/prof/heart/hbp/pphbp.pdf. Accessed on April 9, 2012. 10. Pescatello LS: Exercise and Hypertension: recent advances in exercise prescription. Curr Hypertension Rep 2005, 7:281–286. 11. Pescatello LS, Franklin BA, Fagard R, et al.: American College of Sports Medicine position stand. Exercise and hypertension. Med Sci Sports and Exerc 2004, 36:533–553. 12. Physical Activity and Blood Pressure. American Heart Association. 2012. Available at: http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/PreventionTreatmentofHighB loodPressure/Physical-Activity-and-Blood-Pressure_UCM_301882_Article.jsp 13. Pubmed health: Hypertension. (2011, June 10). Retrieved from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001502/

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18. Wilson, P. American Journal of Hypertension, 1994. vol 7: pp 7S-12S.

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